Air of desperation encircles SIM Summit

The SIM industry has been gathering around Prague for Informa's annual SIM Summit, with various luminaries from the industry presenting their plans for how the SIM is going to develop over the next few years - and the answer seems to be away from mobile phones, if anywhere at all.

The Subscriber Identity Module (SIM), used in every GSM phone and allowing customers to change handset without talking to their operator, has been a key driver for the success of GSM, as well as enabling the bewildering speed of handset development. The SIM creates a secure (enough) connection between subscriber and network, and stores a few SMS messages and phone numbers too.

But the technology has moved on. It's now possible to store several hundred kilobytes on a SIM, and talk to it at high speeds. So customers could, in theory, store music, videos, and applications on the SIM. The problem is that customers haven't shown much enthusiasm for doing so, so this year's SIM Summit was largely filled with presentations expounding what might be possible if only those fickle users would agree to pay for it.

Secure banking

The SIM is a security module, but not secure enough for banking. The GSM security is based on a single secret, with copies stored on the SIM and the Authentication Server at the network operator: if the SIM is going to support secure banking then the bank will have to have access to that secret, or the SIM will have to evolve a more complex security model.

Given that operators are more likely to cut off then own feet than hand over their cryptographic secrets, this is going to mean a more expensive SIM, and handsets to support it.

However, today's handsets can already run a Java application using SSL to speak to a bank's servers: which may well prove secure enough for mobile banking without needing any new SIM technology.

Near field communications

NFC is a very short range radio technology aimed at proximity shopping (waving your phone at a reader to pay for bus tickets and the like). The adoption of USB as the high-speed SIM interface leaves a connection free, which could be used to connect the SIM to an NFC antenna and allow it a new channel to the outside world.

The alternative is to use a secure module on the handset to manage NFC: storing pre-paid balances and such inside the phone. This is the approach appearing on the first NFC handsets, and is certainly in the interests of the handset manufacturers - tying the customer to the handset, not the SIM, so unless network operators rapidly push for ownership on the SIM they're likely to let this one slip through their fingers.

Trial content

The most obvious application for a high-capacity SIM is to stick some content on it, either limited-function trials or some free content to encourage customers to get the hang of personalising.

The problem here is that in order help the customer discover the content they need to have an easy-to-use interface, which must be pre-installed on their phone. But if the application is being pre-installed into the phone memory, then there's no reason not to install the content there too: removing the need to support new SIM standards.

The SIM abroad

More surprising is the suggestion that it's time for the SIM to move out of the mobile phone - acting as a secure module in everything from UMPCs to wrist watches. These applications may well have nothing to do with mobile telephones, just levering the security and utility of the SIM for payment and authentication services.

Desktop computers could really do with a secure module: though the Secure Computing Environment should fulfil many of the roles proposed for the in-computer SIM. Here at the SIM Summit, Laks (maker of posh watches) showed a couple of proximity-payment watches with SIMs fitted inside, and Orange talked of a SIM held in a wrist watch using skin conductance to talk to the phone handset.

But none of these is the SIM as we now recognise it, or offers the billions of sales manufacturers would like to generate.

A solution looking for a problem

SIMs are great. They have been fantastic for the mobile phone business, and continue to provide secure communications in most of the world. In developing markets current SIM technology has been used for banking and payment applications where the operator is willing to work closely with the bank in a trusted relationship.

This year saw a break-away event, the SIMposium, organised in Berlin by the SIM Alliance, an industry group of SIM manufacturers, on exactly the same dates as Informa's get together. Some have interpreted this to mean that the SIM industry is thriving, on the verge of creating new and profitable markets and businesses.

The alternative is to see an industry unwilling to see its product reduced to a commodity status and desperately thrashing around trying to find a killer application that will convince network operators that every SIM needs replacing, not to mention finding a home for all those cool technologies that look so good on PowerPoint slides. ®